qemu_arm64_defconfig: Enable CONFIG_PCI_INIT_R

Replace the "pci enum" preboot sequence with CONFIG_PCI_INIT_R=y.
Signed-off-by: NOvidiu Panait <ovidiu.panait@windriver.com>

configs/qemu_arm64_defconfig

@@ -10,10 +10,9 @@ CONFIG_FIT_SIGNATURE=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_FIT_BEST_MATCH=y
 CONFIG_LEGACY_IMAGE_FORMAT=y
-CONFIG_USE_PREBOOT=y
-CONFIG_PREBOOT="pci enum"
 # CONFIG_DISPLAY_CPUINFO is not set
 # CONFIG_DISPLAY_BOARDINFO is not set
+CONFIG_PCI_INIT_R=y
 CONFIG_CMD_BOOTEFI_SELFTEST=y
 CONFIG_CMD_NVEDIT_EFI=y
 CONFIG_CMD_PCI=y